Read condition-specific symptoms and clinical context for Poliovirus. A mostly silent gut infection that can paralyse a small share of those infected.
CDC states that most people infected with poliovirus have no visible symptoms, while about 1 in 4 have flu-like symptoms and a smaller proportion develop illness affecting the brain and spinal cord. WHO describes polio as mainly affecting children under 5, with one in 200 infections leading to irreversible paralysis. This profile covers the three poliovirus serotypes as a group.
CDC states that most people infected with poliovirus have no visible symptoms, and that about 1 out of 4 have flu-like symptoms that usually last 2 to 5 days and then go away on their own.
Possible symptoms: Sore throat; Fever; Tiredness; Nausea; Headache; Stomach pain.
CDC advises calling a healthcare provider right away or going to an emergency room if polio is suspected. Flu-like symptoms alone do not indicate polio, and most infections cause no visible symptoms at all.
CDC describes the smaller proportion of infections that affect the brain and spinal cord. Frequencies depend on the poliovirus type.
Possible symptoms: Meningitis; Paralysis or weakness in the arms, legs, or both.
CDC states that between 2 and 10 out of 100 people paralysed by poliovirus die because the virus affects the muscles that help them breathe. Post-polio syndrome can affect 25 to 40 out of every 100 polio survivors starting 15 to 40 years after the initial infection; it is not contagious.
Source check: 2026-09-19. Educational content; independent scientific review remains pending.